▍原文 Doubao, a flagship artificial intelligence app developed by Chinese tech company ByteDance, is testing a tiered subscription model that would charge users up to 500 yuan per month. The paid features will target more complex, productivity-driven use cases, including automated PowerPoint generation, deep data analytics and film or video content creation. Industry experts said the move reflects a broader shift across China's AI sector, where companies are racing to prove commercial viability after years of heavy investment. ▍語言點 1. tiered subscription 分層式訂閱，階梯式訂閱 · tiered adj. 分層的；階梯式的 · subscription n. 訂閱；訂購 · cancel a subscription 退訂 · renew a subscription 續訂 2. flagship /ˈflæɡʃɪp/（本文）adj. 旗艦的，王牌的（形容品牌核心產品） 3. paid features 付費功能 · feature n. 特色，功能 4. productivity-driven 以提高生產力為目標的 · productivity n. 生產力，生產率 · XX-driven XX導向的、XX驅動的 5. use case 應用場景 6...